JP2006271396A - Method for counting number of complete virus particles in eluate specimen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for counting the number of complete virus particles in an eluate specimen. <P>SOLUTION: The method for counting the number of complete virus particles in an eluate specimen obtained by a chromatographic operation comprises (a) a step to prepare a standard curve of the number of virus particles at a selected absorbance, (b) a step to perform chromatography on the specimen containing virus particles by using an anion exchange resin, (c) a step to monitor the chromatography in the step (b) at the selected absorbance and (d) a step to compare the absorbance value obtained by the step (c) with the standard curve obtained by the step (a) and determine the total number of the virus particles in the eluate specimen. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for determining the number of complete virus particles in an eluent sample.

BACKGROUND OF THE INVENTION The treatment of disease with gene therapy has moved from theoretical to practical areas. The first human gene therapy attempt was started in September 1990 and involved transferring the adenosine deaminase (ADA) gene to lymphocytes of patients deficient in this enzyme. Lack of ADA activity results in immune deficiency. Viral vectors have been particularly promising in some ways to deliver therapeutic genes to affected cells. Tumor suppressor genes have been studied to treat cancer cells. Viral vectors containing such tumor suppressor genes are being evaluated in the field of cancer therapy as potential therapeutics. Recently, adenoviral vectors have received particular attention as advantageous vectors for the production of such tumor suppressor genes and other biological response modifiers. As cancer gene therapy research moves into clinical trials, more and more purified viral vectors are needed. One problem in producing an appropriate amount of vector for such a test is the purification of the particles from the cell lysate from which the virus particles are produced.

  In particular, purification of these vectors has historically been performed by using a density-based ultracentrifugation method. Although this method has proved effective for use as a research tool, it is not feasible as a method for industrial scale production. Unless new purification schemes can be developed, meeting future material demand will result in prohibitive costs. One alternative to ultracentrifugation is a chromatographic technique for the purification of infectious virus particles.

The use of size exclusion chromatography for the purification of various plant viruses can be accomplished either as a proprietary technique or by augmentation density gradient centrifugation (Albrechtsen et al., J. Biol. Virological Methods 28: 245-256 (1990); and Hewish et al., J. Virological Methods 7: 223-228 (1983). Size exclusion has shown promise for bovine papilloma virus (Hjorth and Mereno-Lopez, J. Virological Methods 5: 151-158 (1982)); and purification of tick encephalitis virus It has been shown to be an excellent method for [
Crooks et al., J. Chrom. 502: 59-68 (1990)]. The use of size exclusion chromatography has not been widespread, but is currently used for large-scale production of recombinant retroviruses [Ment, S .; Jay. (Mento, SJ), Viagen, Inc. (reported at the 1994 Williamsburg Bioprocessing Conference). Affinity chromatography (mostly using monoclonal antibodies (Mabs)) has been reported to be an effective method for the purification of antigens of viral origin [Najayou et al., J. Virological Methods, 32: 67-77 (1991)]. Soybean mosaic virus (a virus that can tolerate pH 3) can be recovered using Mab affinity chromatography [Diaco et al., J. Gen. Virol. 67: 345-351 (1986) ]. Fowler [J. Virologocal Methods, 11: 59-74 (1986)] used affinity chromatography and density gradient centrifugation to purify Bpstein Barr virus.

Adenoviruses are large (about 80 nm in diameter) and somewhat fragile. A large literature base has been accumulated dealing with the relationship between structure and function [for review, see Philipson, Virology 15: 263-268 (1961) and Horwitz, Virology (second edition) Raven
(See Raven Press Ltd, New York (1990)). Little has been reported in the literature regarding chromatographic purification of live adenoviruses. Haruna et al. [Virology 13: 264-267 (1961)] reported the use of DEAE ion exchange chromatography for the purification of type 1, 3 and 8 adenoviruses, and Klemperer and Pereir (Virology 9: 536-545 (1959)) and Philipson (Virology 10: 459-465 (1960)) found it difficult to use the same method with other types of adenoviruses. reported. Poor resolution and poor yield are important issues with this method, which has prevented its use in large scale production.

Thus, there is a need for a chromatographic method for purifying viral vectors such as adenoviral vectors.
J. Virological Methods 28: 245-256 (1990), Albrechtsen et al. J. Virological Methods 7: 223-228 (1983), Hewish et al. J. Virological Methods 5: 151-158 (1982), Hjorth and Mereno-Lopez J.Chrom.502: 59-68 (1990), Crooks, etc. 1994 Williamsburg Bioprocessing Conference, MENT William S. Jay. (Mento, SJ), Viagen, Inc. J. Virological Methods, 32: 67-77 (1991), Najayou and others J.Gen.Virol. 67: 345-351 (1986), Diaco, etc. J. VirologocalMethods, 11: 59-74 (1986), Fowler Virology 15: 263-268 (1961), Philipson Virology (2nd edition) Raven Press Ltd, New York (1990), Horwitz Virology 13: 264-267 (1961), Haruna and others Virology 9: 536-545 (1959), Klemperer and Pareir Virology 10: 459-465 (1960), Philipson

SUMMARY OF THE INVENTION One obstacle in successful examples of gene therapy is the availability of purified viral vectors for extracting therapeutic genes. The present invention involves enzymatic treatment of a cell lysate containing a viral vector containing a therapeutic gene; subjecting the enzyme-treated cell lysate to chromatography on a first resin; and elution from a first column Chromatography of the solution on a second resin: Purifying the viral vector containing the therapeutic gene sufficiently for therapeutic and / or prophylactic use by using a three-step method consisting of: An unexpected and surprising discovery that it can solve the above problems. The resulting purified viral vector with the therapeutic gene retains its infectivity during and after chromatographic processing and can undergo gene transfer. For the first time by using the purification method of the present invention, a chromatographically purified viral vector containing a therapeutic gene is comparable to a viral vector purified using a three day ultracentrifugation method. It was found to be pure and active. The purification method of the present invention offers several advantages over existing methods, including the quality, consistency, reduced process time of purified virus vectors, and the ability to process large volumes of samples. Furthermore, since this new purification scheme is based on the surface properties of virions, this new purification scheme is not only for virions containing different internal DNA constructs with different therapeutic genes, but also for other virions using the teachings of the present invention. Widely applicable. This break-through purification method is an important aspect in the bulk commercialization of gene therapy.

The present invention is a method for determining the number of complete virus particles in an eluent sample from a chromatographic operation comprising:
a) create a standard curve of the number of virus particles at the selected absorbance;
b) Chromatography on samples containing virus particles with anion exchange resin; c) monitoring the chromatography of step (b) at the selected absorbance above;
d) a method comprising measuring the total number of virus particles in the eluent by comparing the absorbance value obtained in step (c) with the standard curve in step (a).
A preferred embodiment of the present invention is the above process, wherein the chromatographic operation is carried out on an anion exchange resin having a QAE group covalently bonded to a polystyrene / divinylbenzene copolymer support.
Thus, the present invention relates to a method for purifying a viral vector containing a therapeutic gene for use in gene therapy. In one embodiment, the present invention provides a method for purifying a recombinant viral vector containing a therapeutic gene from a cell lysate, wherein a) selectively selects both unencapsulated DNA and RNA. Treating the lysate with an enzymatic reagent that degrades; b) on the first resin, subjecting the treated lysate from step a) to chromatography; and then c) on the second resin. The eluate from step b) is chromatographed; in this case one resin is an anion exchange resin and the other resin is an immobilized metal ion chromatography (IMAC) resin. There is a method related.
In another related embodiment, the immobilized metal ion chromatography resin may be substituted with a hydrophobic interaction chromatography resin and / or the anion exchange resin may be substituted with a cation exchange resin.

  In another related embodiment, the enzymatically treated cell lysate undergoes a filtration step that adds a fourth step to the three-step process.

  In a more preferred related embodiment, the purified viral vector is an adenoviral vector containing a therapeutic gene. In an even more preferred embodiment, the adenoviral vector is a recombinant type 5 adenovirus having an internal DNA construct containing a tumor suppressor gene.

Detailed Description of the Invention
a) treating the cell lysate with an enzymatic agent that selectively degrades both non-encapsulated DNA and RNA; b) chromatography the treated lysate from step a) on a first resin. And c) chromatographing the eluate from step b) on a second resin, one of the resins being an anion exchange resin and the other being an immobilized metal ion affinity resin. Relates to a method for purifying a recombinant viral vector containing a therapeutic gene from a cell lysate.

The term “viral vector” means a recombinant virus in which some or all of the genes in the original genome have been removed such that the virus is replication defective.
In addition, the viral vector may be a virus containing a recombinant viral genome containing DNA encoding the therapeutic gene, such that the viral vector is used to transfer the therapeutic gene to a desired human cell for gene therapy. means. Exemplary vectors include those that infect mammalian, particularly human cells, and are derived from viruses selected from the group consisting of retroviruses, adenoviruses, herpesviruses and avipoxviruses. Retroviral and adenoviral vectors are preferred. Adenoviral vectors, particularly type 2 and type 5 adenoviral vectors are particularly preferred. A recombinant type 5 adenovirus vector is most preferred.

  “Therapeutic gene” means a gene encoding a molecule having a desired therapeutic effect or a functional part thereof. For example, a gene that causes an increase in pathological cell growth or proliferation of cells, either due to its absence or mutation. A therapeutic gene as used herein replaces such absent or mutated genes. Therapeutic genes remain in the chromosome so that the gene is expressed by the cell from an extrachromosomal location, or the gene can be integrated into the genome of the cell so that it binds to the endogenous gene. Can cause effects. Such genes are Rb, Rb mutant, p53, p53 mutant, DCC, NF-1, Wilm tumor, NM23, BRCA-1, BRCA-2, BRUSH-1, p56, H-NUC, thyroid hormone Tumor suppressor genes including those selected from the group consisting of receptor genes, retinoic acid receptor genes, genes encoding p130, p107 and p85. Other gene replacement or supplemental strategies include genes encoding adenosine deaminase (ADA), thymidine kinase (TK), various cytokines such as γ-interferon, α-interferon, IL-2 and other hormones.

A therapeutic gene is also understood to include DNA encoding a ribozyme.
Such DNA constructs are selected from the group consisting of selected positive acting growth regulatory genes, eg (1) c-myc, c-fos, c-jun, c-myb, c-ras, Kc and JE A growth factor receptor gene RNA selected from, but not limited to, the group consisting of, but not limited to, oncogenes or proto-oncogenes; (2) epidermal growth factor, platelet-derived growth factor, transferrin and insulin Encodes an RNA enzyme that binds to and breaks down.

  A preferred therapeutic gene is a tumor suppressor gene, and most preferred tumor suppressor genes are Rb, Rb mutant, p53, p53 mutant, BRUSH-1, p56, BRCA-1, BRCA-2, p16 and p21.

  The term “cell lysate” is a cell, such as a host cell containing a vector, preferably a viral vector, which is removed from their growth environment and their cell membranes are removed by physical or chemical means. It means an aggregate of destroyed cells.

  The term “enzymatic drug” selectively degrades non-encapsulated DNA and RNA, but makes the recombinant viral vector non-infectious and transfers an intact copy of the therapeutic gene to the desired target cell Means a compound or mixture that does not decompose to the extent that it cannot be made. Such enzymatic agents are generally endonucleases or a combination of one or more enzymes called DNases or RNases. Benzonase (registered trademark, Benzonase) is a preferred enzymatic reagent.

The term “anion exchange resin” means a positively charged organic moiety covalently crosslinked to an inert polymer support. Exemplary organic moieties include primary, secondary, tertiary and quaternary amino groups such as trimethylaminoethyl (TMAE), diethylaminoethyl (DEAE), dimethylaminoethyl (DMAE) and other groups such as about 5 to about Extracted from polyethyleneimine (PEI) that already has or will have a positive formal charge in the pH range of 9.

  Similarly, representative negatively charged organic groups are from the group consisting of carboxymethyl and sulfonylmethyl groups and other groups that have or will have a negative formal charge in the pH range of about 5 to about 9. Selected.

  The support material should be easily derivatized and have good mechanical strength. The material may be a natural polymeric material, a synthetic polymer or copolymer, or a mixture of natural and synthetic polymers. The support may take the form of porous or non-porous particles, beads, membranes, disks or sheets.

Such supports include silica, hydrophilic polymers [MonoBeads, MonoBeads,
Pharmacia, Piscataway, NJ), cross-linked cellulose [eg Sephacel®], cross-linked dextran [eg Sephadex®], cross-linked agarose [eg Sepharose® Trademark, Sepharose)], polystyrene, or copolymers such as those composed of polystyrene-divinylbenzene or oligoethylene glycol, glycidyl methacrylate and pentaerythrol dimethacrylate, onto which polymer chains of acrylamide derivatives are grafted (The latter copolymer is known as a “tentacle” support).

  The resin can be used in traditional (gravity) column chromatography or high pressure liquid chromatography equipment using radial or axial flow, fluidized bed columns, or in slurry (batch) processes. In the latter method, the resin is separated from the sample by decantation or centrifugation or filtration or a combination of these methods. Viral vectors can be purified by eluting from the resin with a salt gradient, preferably a sodium chloride gradient.

Examples of suitable anion exchange resins are Fractogel® (E. Merck, Gibbstown, NJ) resins derivatized with either DEAE or DMAE; DEAE,. Fractogel derivatized with DMAE or TMAE
EMD tentacle resin; DEAE or QAE derivatized Toyopearl (Toyohers, Montgomeryville, PA) resin; Quat,
Acti-Disk derivatized with DEAE or PEI (Whatman, Clifton, New Jersey) support; Sepharose derivatized with DEAE (Pharmacia, Piscataway, NJ) Resins; including Sephacel® (Pharmacia, Piscataway, NJ) derivatized with DEAE; Sephadex® resin derivatized with DEAE or QAE. Preferred anion exchange resins are derivatized with DEAE groups, and more preferred columns are fructogel, Toyopearl and Streamline (Pharmacia, Piscataway, NJ) DEAE resin.

Similarly, the term “cation exchange resin” means a negatively charged organic moiety covalently crosslinked to an inert polymer support. Exemplary negatively charged moieties include carboxymethyl (CM) and sulfomethyl (SP) groups. Other organic moieties that already have or will have a negative formal charge in the pH range of about 5.0 to about 9.0 are also included within this definition. The above description for supports and methods of use for anion exchange resins applies equally to cation exchange resins. Examples of suitable commercially available cation exchange resins include Sepharose, Sephacel and Sephadex covalently linked to either CM or SP groups.

  "Immobilized metal ion affinity chromatography" ("IMAC") resin means an inert natural or synthetic polymer support covalently crosslinked with a metal chelating group. Metal chelating groups are those known in the art to bind to zinc, nickel, copper, cobalt, calcium or magnesium ions in a formal (+2) oxidation state. Such groups include iminodiacetic acid (IDA) groups, tris (carboxymethyl) ethylenediamine (TED) groups, N- (hydroxyethyl) ethylenediaminetriacetic acid groups, and derivatives such as N- (methyl) and N- (hydroxymethyl). ) Includes the IDA group. These groups can be cross-linked to natural or synthetic polymer supports by standard aliphatic ether linkages and reagents such as bisoxirane, epichlorohydrin and 1,4-bis (2,3-epoxypropoxy) butane. For the method of the present invention, the chelating group can be bound to any of the above metals (metals where zinc is preferred). The description of chemical composition, physical form and use of the polymer support above for the term “anion exchange resin” applies equally to IMAC resins. Cross-linked agarose and “tentacle” supports are preferred. Viral vectors can be eluted from the IMAC column by adding increasing concentrations of competing chelating agents such as imidazole, histamine, glycine or ammonium chloride, and the maximum and minimum range of pH gradient used is about 5 to about As long as it stays at 9, the pH of the eluent may be raised or lowered. Examples of commercially available products that can be used in the method include Acti-Disk IDA cartridges (Whatman), fructogel AF chelate, and Toyopearl AF chelate IMAC resin.

  Furthermore, preferred conditions for the immobilized metal affinity ion resin for purification by DEAE of viral vectors, eg vectors derived from type 5 adenovirus, are from the group consisting of cobalt, nickel, copper, zinc, calcium and magnesium. It has a resin charged with a selected divalent metal cation, and the resin is further an IDA or TED cross-linked agarose resin, in particular an IDA agarose resin charged with zinc ions.

  Hydrophobic interaction chromatography ("HIC") can be substituted for the IMAC resin in the method of the present invention. Such resins have a lower alkyl or aryl group covalently bonded to the inert polymer support through a nonpolar group, such as an aliphatic ether. Lower alkyl groups such as methyl, propyl, n-butyl, neopentyl, and octyl and phenyl are examples of interacting groups on the resin of the present invention. A butyl group is a preferred interactive group. The description of chemical composition, physical form and use of the support above for the term “anion exchange resin” also applies to the HIC resin. Cross-linked agarose, hydroxylated polyether, hydrophilic medium and silica are preferred supports, with cross-linked agarose being most preferred. Viral vectors can be purified by elution from the HIC resin with a decreasing salt gradient (ammonium sulfate is the preferred salt). Examples of commercially available HIC columns useful for the present invention are cross-linked agarose columns such as phenyl-, butyl- and octyl sepharose, and Toyopearl (phenyl, propyl and butyl) and fructogels (propyl or Phenyl).

  As noted above, IMAC or HIC resins in the context of the present invention can be used before or after anion exchange resins. If used before, the salt concentration of the eluate from the HIC or IMAC resin should be diluted to less than about 450 millimoles to prevent premature efflux of virus particles from the exchange resin.

The term “buffering agent” or “buffered solution” refers to acids and bases that, if present in solution, reduce or mitigate pH changes that would occur in solution when acid or base is added. Means a mixture of In one embodiment, the cell lysate is maintained in a buffered solution. Suitable buffering agents are those that can maintain the pH of the resulting solution between about 5.0 and about 9.0. Such buffers are commercially available and can be used as phosphate, MES, HEPES, MOPS, borate, TRIS, BES, ADA, ACES, PIPES, MOPSO, BIS-TRIS PROPANE, BES, TES, DIPSO, TAPS
O, TRIZMA, HEPPSO, POPSO, TEA, EPPS, TRICINE, GLYCYLGLYCINE, BICINE, TAPS and the like are included. Preferred buffering agents include phosphate, MES, HEPES, MOPS, borate and TRIS, with HEPES being most preferred.

  The use of chromatography to purify viral vectors, eg, adenoviral vectors called type 5 for use in gene therapy, has been shown to be an effective alternative to cesium chloride density gradient ultracentrifugation. This methodology has various advantages such as quality, consistency, reduced processing time, system automation and the ability to process large amounts of crude lysate. The purification scheme described in the present invention selects products based on virion surface characteristics. These characteristics do not change with different internal DNA constructs with different therapeutic genes in the construct, for example, and therefore lead to similar chromatographic responses. In other words, chromatography is not affected by the nature of the therapeutic gene inserted into the vector.

The anion exchange resin, immobilized metal ion affinity chromatography resin, cation exchange resin and hydrophobic interaction chromatography resin are washed using methods known to those skilled in the art. For example, DEAE is treated first with NaOH, then with HCl, and finally with NaCl. IZAC is EDTA first, then NaOH, HCl, NaCl flush with H ₂ O
Along with each stage. The column is equilibrated with a suitable buffer using suitable binding conditions. The column adjusts the pH and salt concentration for DEAE, and the product binds to the resin by adjusting the pH, salt concentration and divalent metal ion concentration for the immobilized metal ion affinity column. A sample in a buffer will be injected. The column can be washed to remove contaminants and reused.

  Another aspect associated with the present invention includes the additional step of filtering the cell lysate after treatment with the enzymatic agent. In another related embodiment, the cell lysate is buffered prior to treatment with benzonase to a pH between about 5.0 and about 9.0 before injecting (applying) it to the first resin. . These embodiments are preferred for the purification of recombinant viral vectors derived from either retroviruses or adenoviruses, and are particularly preferred when the vectors are derived from adenoviruses, and such vectors are tumor suppressor genes Containing.

  Another embodiment for purifying an adenovirus-derived vector containing a tumor suppressor gene is that the treated buffered cell lysate is first chromatographed on an anion exchange resin and then on an immobilized metal affinity resin. In which chromatography is performed.

  These conditions are particularly preferred when the recombinant viral vector is derived from a type 2 or type 5 adenovirus, particularly a type 5 adenovirus.

The enzymatic agent used to treat the cell lysate is one or more enzymes, particularly those selected from the group consisting of RNases and DNases, as known to those skilled in the art, or It is a mixture of endonucleases. Preferred enzymatic agents for use in this embodiment are Benzonase®, a recombinant non-specific nuclease that cleaves both RNA and DNA.

  Finally, a particularly preferred related method of what has been described so far is when the type 5 adenovirus-derived recombinant viral vector has a genome containing the wild type p53 gene.

This specification includes inventions of the following embodiments.
1. A method for purifying a recombinant viral vector containing a therapeutic gene from a cell lysate, comprising a) treating the cell lysate with an enzymatic agent that selectively degrades both non-encapsulated DNA and RNA;
b) chromatography of the treated lysate from step a) with a first resin; and c) chromatography of the eluate from step b) with a second resin, Wherein one resin is an anion exchange resin and the other is an immobilized metal ion affinity resin.
2. 1. The first resin is an anion exchange resin and the second resin is an immobilized metal affinity resin. The method described in 1.
3. 2. including the additional step of filtering the treated lysate from step (a). The method described in 1.
4). 2. including the additional step of buffering the pH of the cell lysate between about 5.0 and about 9.0 prior to application to the first resin. The method described in 1.
5. 3. The recombinant virus vector is a retrovirus. The method described in 1.
6). 3. The recombinant virus vector is an adenovirus. The method described in 1.
7). 5. The therapeutic gene contained in the recombinant adenoviral vector is a tumor suppressor gene. The method described in 1.
8). 6. The recombinant adenoviral vector is type 2 or type 5 adenovirus. The method described in 1.
9. 7. The recombinant adenovirus vector is a type 5 adenovirus. The method described in 1.
10. 8. The tumor-suppressor gene is a wild type p53 gene. The method described in 1.
11. 2. The anion exchange resin is selected from the group consisting of DEAE, TMAE, DMAE, QAE and PEI. The method described in 1.
12 10. The anion exchange resin is DEAE resin. The method described in 1.
13. 2. The immobilized metal affinity resin is charged with a divalent cation of a metal selected from the group consisting of cobalt, nickel, copper, zinc, calcium and magnesium. The method described in 1.
14 12. The immobilized metal affinity resin is a TED or IDA resin. The method described in 1. 15. 13. The immobilized metal affinity resin is IDA- (crosslinked agarose) resin. The method described in 1.
16. 15. The divalent cation is zinc. The method described in 1.
17. The aforementioned 1. wherein the enzymatic agent that selectively degrades both non-encapsulated DNA and RNA is one or more enzymes. The method described in 1.
18. The above 17. wherein the one or more enzymes are endonucleases The method described in 1.
19. 18. The enzyme as mentioned above, wherein the enzyme is benzonase. The method described in 1.
20. A method for purifying a recombinant viral vector containing a therapeutic gene from a cell lysate; a) treating the cell lysate with an enzymatic agent that selectively degrades both non-encapsulated DNA and RNA;
b) chromatography on the treated lysate from step a) on a first resin; and c) chromatography on the eluent from step b) on a second resin,
In the above, one resin is an anion exchange resin and the other is a hydrophobic interaction chromatography resin; or one resin is a cation exchange resin and the other is a hydrophobic interaction chromatography resin or an immobilized metal. A method that is any of an ion affinity resin.
21. 21. One resin is an anion exchange resin and the other is a hydrophobic interaction chromatography resin. The method described in 1.
22. 21. The first resin is an anion exchange resin and the second resin is a hydrophobic interaction chromatography resin. The method described in 1.
23. 21. One resin is a cation exchange resin and the other is an immobilized metal ion affinity resin. The method described in 1.
24. 21. One resin is a cation exchange resin and the other is a hydrophobic interaction chromatography resin. The method described in 1.
25. A method for determining the number of complete virus particles in an eluent sample from a chromatographic operation comprising:
a) create a standard curve of the number of virus particles at the selected absorbance;
b) Chromatography on samples containing virus particles with anion exchange resin; c) monitoring the chromatography of step (b) at the selected absorbance above;
d) A method comprising measuring the total number of virus particles in the eluent by comparing the absorbance value obtained in step (c) with the standard curve of step (a).
26. 25. The chromatographic operation is performed on an anion exchange resin having a QAE group covalently bonded to a polystyrene / divinylbenzene copolymer support. The method described in 1.

Experimental part
Step 1 ACN53 reference material (CsCl-ACN53)
The standard recombinant adenovirus type 5 designated ACN53 is a vector derived from a type 5 adenovirus having a sequence encoding F1 with a full length 1.4-kb p53 cDNA driven by a human cytomegalovirus promoter. (Wills et al. Human Gene Therapy 5: 1079-1088 (1994)). The virus is described in (Laver et al., Virology 45: 598-614 (197
The three-stage centrifugation method described in 1)) is modified as follows. Infected cells were lysed by three freeze-thaw cycles and centrifuged at 15,000 rpm for 10 minutes at 4 ° C. in a Sorvall RC-5B centrifuge. The pellet was discarded and the supernatant was treated with Benzonase ^™ at 133 U / mL at room temperature for 30 minutes. The treated material was then placed in layers on a 1.25 g / mL and 1.40 g / mL CsCl non-continuous step gradient in 10 mM Tris pH 8.1 and 75 ° C. at 30,000 rpm in a Sorvall TST 41-14 rotor. Centrifuge for minutes. Viral bands from each tube were collected, mixed with 1.35 g / mL CsCl (10 mM Tris pH 8.1), and centrifuged at 45,000 rpm, 10 ° C. in a Beckman VTi 50 rotor. Viral bands from each tube were collected and centrifuged at 45,000 rpm for an additional 4 hours as before. The final virus pool from this stage was dialyzed extensively at 4 ° C. against phosphate buffered saline (PBS) supplemented with 2% sucrose and 2 mM MgCl ₂ . The purified virus pool was used to infect human embryonic kidney 293 cells (purchased from ATCC (American Type Culture Collection)) as described in Step 2 below.

Step 2 Growth and collection of ATCC293 cells and lysis ATCC293 (ATCC CRL 1573) cells in a CO ₂ incubator, 1.5 L of Cell Factory ^™ (Nunc, Ruschilde) in a culture medium having the following composition:
, Denmark) [DME high glucose broth containing 10% Hyclone bovine serum as defined, 2 mM glutamine (Irvine Scientific, Santa Ana, California), 1 mM sodium pyruvate (Irvine Scie
ntific). Antibiotics are not added to the culture. ].
Two to two and a half days after inoculation with Cell Factory ^™ , when about 50-60% of the cell monolayer merges, the cells are infected with 500 mL of fresh culture solution with multiple infections (MOI) of 5-10 infection units per cell. did. Virus was added to the culture, stirred well and introduced into the cells in the unit.
When the cell monolayer from Preparation 1 showed signs of detachment from the surface of Cell Factory ^™ (usually 3-4 days after infection), slowly remove cells and collect in Beckman TJ-6 Centrifuge for 5 minutes at 1500 rpm. They are washed once with serum-free medium, pelleted again and 25 mL of 50 mM Tris buffer pH 8.0 / 150 mM N for use in the preparation of ultracentrifugation-derived standard virus.
Resuspended in aCl, 2 mM MgCl ₂ , 2% sucrose. Samples intended for use throughout Examples 1-3 were resuspended in 25 mL of 50 mM HEPES buffer pH 7.5 / 150 mM NaCl, 2 mM MgCl ₂ , 2% sucrose. Cells are frozen-thawed at this point 3
Lysis by cycle. Following the third cycle, cell debris was removed by centrifugation in Beckman TJ-6 at 1500 rpm, 4 ° C. for 5 minutes.

Step 3 Western Blot Analysis of Samples Containing Recombinant Adenovirus Particles SDC-PAGE gels were run as described in Example 3, Step F, with approximately the same amount added to the silver stained gel. The band was then transferred to a PVDF membrane pre-wet with 100% methanol and equilibrated in Tris buffered saline (TBS). The gel was also equilibrated in TBS. The protein was transferred to the membrane using a Bio-Rad semi-dry transfer apparatus at 25 V for 30 minutes. The membrane was then blocked with 1% casein / 0.01% sodium nitride overnight at 4 ° C. or room temperature for 1 hour and washed 3 times with TBS. The membrane was incubated with the first antibody (Cytimmune rabbit IgGa-adenovirus type 5, Lee Biotechnology Research: San Diego, Calif.) 5 μg / mL (in TBS) for 1 hour at room temperature. Following the first incubation, the membrane was washed 3 times with TBS and the second antibody (Amersham Life Sciences, Arlington Heig)
(hts, IL)
Horserradishperoxidase conjugated anti-rabbit Ig) diluted in 1 μL stock antibody / 1 mL TBS) and incubated at room temperature for 1 hour. The last three washes were performed with TBS and the membrane was incubated with Amersham ECL detection reagent for 1 minute for various times in the dark (several seconds to minutes to select different controls), hyperfilm (Hyperfilm ) -ECL (Amersham) and developed in X-ray film developer.
Using this Western blot analysis, the difference between the band patterns of ACN53 in various purification states can be seen in FIG.

Step 4 Determination of the number of recombinant adenovirus particles by absorbance at 260 nm in the presence of SDS For this measurement, the concentrated virus is diluted to 1 in 10 in 0.1% SDS in phosphate buffered saline (PBS). The sample was vortexed for 1 minute and centrifuged at 14,000 rpm in an Eppendorf microfuge to remove the precipitate. Match matching pairs of cuvettes with PBS
Blanks are determined by writing baseline scan lines on a Shimadzu UV160U spectrophotometer (Shimadzu Scientific Instrument, Columbia, MD.) Using 0.1% SDS in buffer. The SDS treated virus sample was then placed in a sample cuvette and scanned from 220 nm to 340 nm. If there was an absorbance between 310 and 320, the sample was too dark and was further diluted and remeasured. A ₂₅₀
The / A ₂₈₀ ratio is also determined from this scan, and it must be between 1.2 and 1.3 to ensure that it is pure enough to measure the particle number. If this condition is met, the absorbance at only 260 nm is used to calculate the virion / mL number. Conversion factor of 1.1 × 10 ¹² particles per absorbance unit at 260 nm (Maizel et al
. , Virology 36: 115-125 (1968))
Was used with an error of about 10% to calculate the number of particles. Typical values for samples subjected only to anion exchange chromatography (ie Examples 1 and 2 using DEAE resin) were between 1.14 and 1.19. When such samples were subjected to IZAC as described in Example 3, the ratio was in the range of 1.22 to 1.25.

Lysis nuclease treatment of unencapsulated nucleic acids The lysate of infected cells initially consists of both host cell and viral contaminants.
Some of these contaminants are removed prior to chromatography. In particular, host cells, unencapsulated or incomplete ACN53 nucleic acids were enzymatically degraded at this stage of the process using nucleases such as Benzonase ^™ . This may be done early in the process for two reasons. The initial Benzonase ^™ treatment improves the yield in the anion exchange resin. Benzonase ^™ was removed in the next process step. The presence of Benzonase during the process was determined using a commercially available ELISA kit (American Internationala).
l Chemical, Natick, MD).
Clarification of the treated lysate was performed by filtration rather than centrifugation. Slow rotation was used to remove cell debris (Figure 1). Filtration was then used to prepare the product for loading on the first column. The type of filter media used (ie, composition and pore size) and its effective product recovery was assessed by the quantitative anion exchange assay described in Example 3, Step A.
Following centrifugation, Gelman Sciences Acrodisc ^™ 0.8 / 0.2 μm.
The two-stage cylindrical filter was passed through. The recovery of ACN53 was dependent on the pore size and membrane type used for filtration. Filter media such as membranes based on polysulfone membranes, PVDF membranes and cellulose acetate membranes were used. Polysulfone and PVDF were preferred.
The supernatant liquid at this stage was mixed with MgCl _{2 2} mM, sucrose 2% (wt / vol) and β
-The cyclodextrin was 2.5% (wt / vol). Benzonase ^TM (Amer
ican International Chemical, Inc. ) Was added to a final concentration of 100 units / mL and incubated at room temperature for 1 hour. Treated material was centrifuged in Beckman TJ-6 at 3000 rpm for 10 minutes and Gelman Scie.
Clarified by filtration through a Nces Acrodisc ^™ 0.8 / 0.2 μm filter. The resulting supernatant was collected for Example 2.

Throughout the anion exchange chromatography, the characteristics of DEAE chromatography were found to be consistent, and loading tests with high concentration lysate (3 × 10 ¹² ACN53 particles / mL) were recovered with the injected volume. Linear response between ACN53 peak regions
showed that. Elution of the DEAE column with the introduction of a linear salt gradient showed three major peaks. The first of these peaks was a protein peak with an _A260 / _A280 ratio of about 0.5. The following is ACN53 peak (A ₂₆₀ / A ₂₈₀ = 1.23
Followed by a DNA (A ₂₆₀ / A ₂₈₀ = 2) peak at the end of the gradient.
The same peak was obtained with either HEPES, Tris buffer or phosphate buffer system. Although the pH can be changed, operating at pH 7.5 using HEPES pH 7.5 / NaCl / sucrose / MgCl ₂ will adsorb less contaminating material onto the column. DEAE chromatography provides a high degree of initial purification. The immobilized metal ion purification chromatography step removes these contaminants.
The column resin was tested for its separation performance in a 6.6 × 50 mm (1.7 mL) borosilicate Omnifit ^™ column (Omnifit Ltd., Cambridge, England).
The column was mounted on a PerSeptiv Biosystems Biocad ^™ (Cambridge, MA) chromatography workstation. Chromatography was tracked and investigated online for pH, conductivity and optical density at two wavelengths of 280 nm and 260 nm.
Anion exchange resin is 50 mM HEPES, pH 7.5, 300 m at 1 mL / min.
Equilibrated with MNaCl, 2 mM MgCl ₂ , 2% sucrose. A 50 mM Tris buffer pH 8.0 (containing 300 mM NaCl, ₂ mM MgCl ₂ , 2% sucrose) was also used. After filling with cell lysate, it was followed by absorbance and washed to baseline, elution was performed with 20 column volumes of 300-600 mM primary NaCl gradient and 0.5 mL fractions were collected. For future use, the column was then cleaned with 2 column volumes of 0.5 M NaOH, 1.5 M NaCl wash and then re-equilibrated.
In order to obtain an appropriate control retention time, CsCl-ACN53 was injected at 2 mL / min (350 cm / hr) onto a DEAE column equilibrated in 50 mM Tris pH 8, and 0-1.5 for 10 min (11.7 column volumes). Eluted with M primary NaCl gradient. 1.23 A ₂₆₀ / A ₂₈₀ was detected. The protein band present in this fraction reacted with the Ad5 polyclonal antibody on slot-blot analysis.
Several peaks were resolved when the infected cell lysate sample was applied to the DEAE column (Figure 2). The peak composition was estimated from the A ₂₆₀ / A ₂₈₀ extinction ratio. For example, the first peak is 0.5
It is mainly protein because it has a ratio of _A260 / _A280 . The third peak has an A ₂₆₀ / A ₂₈₀ ratio of 2, implying that this material is a nucleic acid. The ACN53 virus peak eluted second with a ratio of 1.23. The identity of these peaks was confirmed by modifying the experiment and passing each peak through an SDS gel. In a typical test using the conditions described above, an A ₂₆₀ / A ₂₈₀ ratio of 1.23 ± 0.8 was found to be characteristic of the virus peak.
In order to evaluate the purification ability of DEAE chromatography, both uninfected ATCC-293 cell lysate and CsCl-ACN53 were applied to the column (FIG. 3). Although most of the host cell material passed through the column during loading or eluted earlier than the retention time of ACN53, a small peak eluted at the same retention time as ACN53. From these data, the non-viral contaminant of the ACN53 peak is expected to be from host cell material. Examination of the contamination peak, ie the last eluting peak in the cell lysate sample shown in FIG. 3, revealed an A ₂₆₀ / A ₂₈₀ nm ratio of about 2. This indicates that the peak has a high nucleic acid content and can be reduced or eliminated by nuclease treatment. DEAE manipulations with or without Benzonase ^™ pretreatment showed that the enzyme reduced the amount of contaminants from host cells in the ACN fraction pool.

Immobilized Metal Affinity Chromatography Immobilized metal affinity chromatography (IMAC) using zinc atoms as divalent cations (IZAC) gives high product recovery and also allows the DEAD fraction pool to be loaded before loading. No sample manipulation was required. Impurities removed by this method elute in the effluent peak and dissolve well from the product, leading to the Simpler pool standard. IZAC is reproducible and when used with DEAE yields pure ACN53, specified by SDS-PAGE gels and Western blots, A ₂₆₀ / A ₂₈₀ ratio and ratio of infecting particles to non-infecting particles It is possible to provide a two column purification protocol. The overall protocol summarized is as follows:
Bacterial cells
↓
Nuclease treatment
β-cyclodextrin treatment
↓
Clean
↓
DEAE chromatography
↓
IZAC chromatography
↓
Buffer exchange The recovery by step for all particles and infectious units is summarized in Tables 1 and 2 in the experimental section.
Metal charge the immobilized zinc affinity chromatography (IZAC) system by washing the column successively with 1 volume of 100 mM EDTA and 1 volume of 0.2 M NaOH with flushing with water after each step. Prepared for. The matrix was subsequently charged with zinc atoms by injecting a column volume of 100 mM ZnCl ₂ in H ₂ O acidified with 0.5 μL / mL glacial acetic acid. The matrix was then washed thoroughly in water prior to equilibration in 50 mM HEPES pH 7.5 / 450 mM NaCl / 2% sucrose / 2 mM MgCl ₂ . Sample loading did not require any manipulation, and the DEAE pool fraction or CsCl derived material was injected directly into the column. After loading, the column was loaded with 50 mM HEPES pH 7.5 / 450 mM NaCl / 2% sucrose / 2 m.
Wash with a 10 column volume decreasing NaCl linear gradient from M MgCl ₂ to 50 mM HEPES pH 7.5 / 150 mM NaCl / 2% sucrose / 2 mM MgCl ₂ . Elution was performed with a 0 to 500 mM linear glycine gradient (in 150 mM NaCl) to which more than 10 column volumes were applied.
The interaction of ACN53 with the metal affinity column shows metal-specific properties (zinc atoms are preferred) and injection of CsCl-ACN53 into uncharged columns (columns not preloaded with zinc atoms) is generated This resulted in a shift of the product peak to the runoff. Example 2 IZAC purified ACN53-DEAE from the fraction pool is shown in FIG. Analysis of IZAC fraction pool to 65% yield and 1.22 to no 49 produced an A ₂₆₀ / A ₂₈₀ ratio of 1.25. A gel and Western blot comparison of CsCl-ACN53, DEAE purified and DEAE / IZAC purified material can be seen in FIGS. CsCl-ACN53 and DEAE / IZAC materials are very similar, and materials purified with DEAE alone are less pure than these standards.
The effects of different IZAC buffers and elution systems were evaluated by splitting the DEAE-ACN53 pool in half and purifying both halves with IZAC in HEPES pH 7.5 and Tris pH 8 buffer systems. IZAC was also performed in the presence of sucrose and MgCl ₂ without affecting the separation. The use of copper as the metal ion and imidazole as the elution reagent was also tested (see Belew et. Al. 1987, Kato et. Al. 1986 for a general review of metal affinity chromatography). Various systems, zinc / glycine, zinc / imidazole, copper / glycine and copper / imidazole all worked on the metal affinity purification column. ACN53 can be eluted using a gradient from pH 7 to pH 9.

^a分析的イオン交換により決定
^bウイルス粒子数における
^c最終配合物への透析後 A: Assay for number of recombinant adenovirus particles by anion exchange HPLC A 1 mL Resource Q (Pharmacia, Piscataway, NJ) anion exchange column was used to quantify the number of virus particles in various samples. The column was equilibrated in a Waters 625 chromatography system equipped with a 717 plus autosampler and 991 light emitting diode array detector (PDA) at a flow rate of 1 mL / min in 300 mM NaCl, 50 mM HEPES, pH 7.5. Chromatography was monitored with a PDA detector (Milford, Mass.) Scanning from 210 to 300 nm. A standard line was evaluated for all particles at a selected absorbance, A ₂₆₀ in 0.1% SDS, CsCl purified A
Made by injecting CN53 virions.
The assay was independent of the volume of sample injected. After loading the sample, the column was loaded with 2 column volumes of equilibration buffer followed by 50 mM HEPES, pH 7.
Wash with more than 10 column volumes of a 300 to 600 mM NaCl linear gradient in 5. The gradient was followed by two column volume washes with 600 mM NaCl in 50 mM HEPES, pH 7.5.
After each chromatography run, the column is 50 mM HEPES, pH 7.
Cleaned with 2.6 column volumes of 1.5 M NaCl in 5 and then re-equilibrated for the next injection. The column was cleaned more strongly after injection of the crude sample by injection of 0.25 to 1 column volume of 0.5N NaOH followed by a wash with 1.5M salt. Injection of NaOH and subsequent spilling of the gradient was a convenient way to achieve cleaning. The use of the assay in measuring the total number of adenovirus particles present is illustrated in Table 1 below. Table 1: Yield and purification data based on total ACN53 particles

^{aDetermined by} analytical ion exchange
^{b in} virus particle count
^cAfter dialysis to the final formulation

B: Buffer conditions Changes in buffer conditions were used for purification of ACN53 by column chromatography in this study in the pH range of 7.0 to 8.0 (eg Seth, Virology 68: 1204-1206
(1994)). Investigations for decay at various pH limits are performed by assaying for decay by TCID50 (Method C below) and analytical anion exchange analysis (Method A above). The effect of buffer salt concentration on ACN53 viability indicated that a rapid change in ionic strength would lead to virus loss. Salt concentration should be carefully controlled and monitored.

全ウイルス粒子の感染するウイルス粒子に対する比は製造ごとに広範囲に変化することができる。ＣｓＣｌ誘導されたウイルスについての値は６０ないし８０の範囲である。粗溶解液または半精製画分におけるこの比の計算は、アニオン交換粒子アッセイ（実施例３［Ａ］）を見よ。）によって可能とされた。分析的アニオン交換を使用して、理想的なウイルス粒子の感染するウイルス粒子に対する比における変化を監視することができる。本発明の精製方法を使用して、粗溶解液および続いて精製される物質の全ウイルス粒子の感染するウイルス粒子に対する比を、超遠心分離を使用して得られたものと比較することができる。アッセイの誤差内において、これらの値は等価である。この基準により、クロマトグラフ精製にウイルスは良い耐性がある。他の基準、すなわちＳＤＳ−ＰＡＧＥおよびウエスタンブロッド分析（図６および７）により、クロマトグラフ精製は超遠心分離に基づいた方法より優れている。 C: Measurement of Infecting Recombinant Adenovirus Particles by TCID ₅₀ Assay Quantification of infecting adenovirus Type 5 particles prior to, during and after the purification method taught in these examples was performed using an endpoint titer assay (tissue culture infection rate). -50%, performed by abbreviations _{TCID 50) (Philipson, Virology 15} : 263-268 (1961) and see).. Reagents, substance lists and descriptions can be used from Chemicon International, Inc (cat. # 3130: “Adenovirus Direct Immunofluorescence Assayi”, Temecula, Calif.).
ATCC293 cells are plated in 96-well plates and 100 μL of 5 × 10 ⁵ cells / mL for each well in complete MEM (10% calf serum, 1% glutamine) culture medium. In each plate, a 250 μL aliquot of virus sample diluted 1:10 ⁶ is added to the first column and serially diluted 2-fold across the plate. One row is saved for positive control (CsCl purified ACN53) and one row for negative control. A 100 μL aliquot of each hole was transferred to the same position on the ATCC-293 seeding plate and cultured at 37 ° C. in a humidified incubator for 2 days. The culture was then decanted by inversion and the cells were fixed with the addition of 50% acetone / 50% methanol. After washing with PBS, the fixed cells are incubated for 45 minutes with FITC-labeled anti-ad5 antibody (Chemicon International # 5016) prepared according to the kit instructions. After washing with PBS, the plates were examined under a fluorescence microscope (490 nm excitation, 520 nm emission) and scored for the presence of the label. Titers were quantified using the Titerprint Analysis program (Lynn, Bio Techniques , 12: 880-881 (1994)). The results from assays performed according to this method are set forth in Table 2 below, which includes ratios calculated using the values from Table 1 above.
Table 2: Yield and purification data based on infecting ACN53 particles.

The ratio of total virus particles to infecting virus particles can vary widely from production to manufacture. Values for CsCl induced viruses range from 60-80. See the anion exchange particle assay (Example 3 [A]) for calculation of this ratio in the crude lysate or semi-purified fraction. ). Analytical anion exchange can be used to monitor changes in the ratio of ideal virus particles to infected virus particles. Using the purification method of the present invention, the ratio of crude lysate and subsequently purified material to total virus particles to infecting virus particles can be compared to that obtained using ultracentrifugation. . Within the assay error, these values are equivalent. By this criterion, the virus has good resistance to chromatographic purification. By other criteria, SDS-PAGE and Western blot analysis (FIGS. 6 and 7), chromatographic purification is superior to methods based on ultracentrifugation.

D: Assay for Infecting Recombinant Adenovirus Particles by Expression of P53 Protein Virus product activity was also tested by assaying for expression of p53 gene product in Saos-2 cells, p53-negative osteosarcoma cell line . Kaih's nutritional mixture F12: D supplemented with Saos-2 cells in 6-well tissue culture plates at a concentration of 5 × 10 ⁵ cells / well with medium, 2 mM L-glutamine and 10% fetal calf serum
Seed in 3 mL of ME High Glucose (1: 1 mixture). Cells were cultured in humidified air at 7 ± 1% CO ₂ at 37 ° C. for 16-24 hours. The spent media was removed and replaced with 1 mL of fresh media and the cells were infected with 20, 40, or 60 MOI of purified virus. After 1 hour of culture, an additional 2 mL of culture was added and allowed to grow for 8 hours. The cells were then washed once with Dulbecco's-PBS, and 50 mM tris / 0.5% Nordite P-40 / 250 mM NaCl / 5 mM EDTA / 5 mM NaF / 5 μg / mL Leupeptin and 5 μg /
Dissolved by the addition of 250 μL of mL Aprotinin / 2 mM PMSF. Plates were incubated on ice for 5 minutes, after which the lysate was transferred to individual 1.7 mL microcentrifuge tubes. They are spun down in a microfuge at 14000 rpm for 45 seconds and the supernatants are primary anti-p53 monoclonal antibody 1801 (Vector Laboratories, Burlingame, California) and sheep anti-mouse IgG by Western blot analysis for the presence of p53 protein. Assayed with a 1: 1 mixture of HRP as well as streptavidin-HRP (Amersham). The p53 protein band was detected using the Amersham's ECL detection kit according to the manufacturer's instructions. The results of using the assay are shown in FIG. The expression of p53 can be seen in ACN53 purified only by DEAE chromatography and by both DEAE and IZAC chromatography. (The low level expression in lanes 5 and 6 is due to the fact that these samples were performed at a lower MOI than the DEAE samples.)

E: Host cell protein contaminants Host cell contaminants were assayed using polyclonal antibodies generated and differentiated against ATCC-293 cell components by Western blot analysis. Polyclonal antibodies were obtained commercially and raised against various 293 cell antigens (HTI, Ramona, CA). The results showed that the final purified product of CsCl or DEAE-IZAC was free of detectable host cell contaminants. In the case of semi-purified DEAE-ACN53, there was a small amount of immune contaminants found in the purified pool, three main bands and several small ones. Most of the host cell contaminants are recovered in the effluent of the DEAE stage. Contaminants co-purified in the DEAE step with ACN53 were removed by zinc affinity chromatography and collected in the IZAC effluent fraction prior to insertion of the glycine gradient.

F: SDS-PAGE analysis sample containing recombinant adenovirus particles 100-200 μL of adenovirus-containing sample (about 1 × 10 ¹¹ particles / mL) is collected for Coomassie-blue coloration and trichloroacetic acid precipitation is performed. Or desalinate by dialysis and subsequent concentration in a speed-vac. Sample is then SDS-PAG
E reducing buffer (125 mM Tris-HCL, pH 6.8, 20% glycerol, 4
% (W / v) SDS, 0.005% bromophenol blue, 0.5% β-mercaptoethanol), resuspended to approximately 30 μL, boiled for 5 minutes and 1 mm × 10 well Novex 8-16% gradient Tris -Loaded into Glycine minigel. Sample 1.5
Electrophoresis was performed at 140V for a time. The gel was then fixed in 40% methanol / 10% acetic acid for 30 minutes and then the Coomassie was colored with Pro-Blue coloring system (Integrated Separation Systems, Natick MA) according to the vendor's method.
A 5-15 μL sample was loaded onto the silver colored gel. Samples were boiled with an equal volume of reducing buffer and electrophoresed as described for Coomassie detection. Fixing was performed by treating the gel in 10% trichloroacetic acid for 1 hour, followed by washing 3 times in water purified to 18 megohm. The gel was colored according to the instructions given in the Daiichi silver coloring kit (Integrated Separation Systems).

Vector infectivity, therapeutic gene transfer The evaluation of DEAE-IZAC-ACN53 is
Virions can retain their infectivity during chromatography as measured by TCCID ₅₀ (Tables 1, 2) and can result in gene transfer as assayed by P53 protein expression in Saos-2 cells. This is shown. Comparison of this DEAE-IZAC-ACN53 in SDS-PAGE to CsCl-ACN53 shows that there is a lower molecular weight protein band present in CsCl-ACN53. A side-by-side comparison of the different CsCl-ACN53 lots shows some batch-to-batch variability, whereas the chromatographically produced material matches very well. The overall ratio to infecting particles and the absorption spectra of both types of substances can be directly compared. Evaluation of chromatographically produced ACN53 for purity and activity shows that the two-column method per day can replace the three-day ultracentrifugation protocol.
A preferred purification scheme as shown above for ACN53 is to treat the infected cell lysate with Benzonase ^™ prior to the chromatography step. Cleaning is then performed by a filtration step through a 0.8 μm and subsequent 0.2 μm membrane. If necessary, a large pore (eg 5 μm) prefiltration step can be added for further viscous suspension. Adjustment to pH 7.5 / 300 mM NaCl is then made in preparation for loading on the DEAE column. Purified peaks as detected by the A ₂₆₀ / A ₂₈₀ nm ratio or by characteristic light emitting diode array spectra are pooled and injected directly into a zinc-charged, equiosmotic equilibrated metal affinity column. The The ionic strength of the buffer is then gradually reduced to approximately phosphate buffered saline (approximately 150 mM NaCl) prior to elution of the product with a glycine gradient. This material is then dialyzed into the final formulation.

Brief description of the figure
FIG. 1: Recovery of ACN53 from crude infected cell lysate supernatant centrifuged at 5 ° C. for 5 minutes in an Eppendorf centrifuge model 5415c at 4 °. Analysis for ACN53 was performed by analytical anion exchange. FIG. 2: Identification of ACN53 infected cell lysate components and separation by DEAE chromatography by dual wavelength UV absorbance using 60/280 nm absorbance ratio. Figure 3: CsCl-ACN53 control and host-cell contaminant retention time during DEAE purification. The elution of CsCl-ACN53 is compared to the elution of an uninfected H293 host cell lysate blank chromatographed on a DEAE column. FIG. 4: Butyl-Hydrophobic Interaction Chromatography of DEAE-ACN53 fraction pool. A semi-pure DEAE purified ACN53 fraction pool was mixed with an equal volume of 50 mM Tris / pH 8.0 / 3M ammonium sulfate and then injected onto a TosoHaas Butyl-650M column, then Elute with an ammonium sulfate gradient decreasing to 1.5-0M. FIG. 5: Immobilized metal affinity chromatography of DEAE-ACN53 fraction pool. A semi-pure DEAE purified ACN53 fraction pool was injected onto a 6.6 × 50 mm TosoHas AF chelate 650M column loaded with ZnCl ₂ and then a linear 0-500 mM glycine gradient Eluted with. FIG. 6: SDS-PAGE control of ACN53 derived from column chromatography and CsCl-ultracentrifugation. Samples were electrophoresed on 8-16% gradient polyacrylamide gels and then stained with silver for analysis. Lanes 2 and 3 are DEAE and IZAC eluate pools, respectively. Lanes 4-6 show three different lots of CsCl-ACN53 runs (CsCl-1, CsCl-2 and CsCl-3) in order to check the consistency between lots. In lane 7 (CsCl-ion exchanged lot), a sample of CsCl-ACN53 derived from the ion exchanged lot is purified on a Resource Q anion exchange HPLC column [Resource Q, Pharmacia]. Shows the ACN53 peak recovered in some cases. Lanes 1 and 8 are standard molecular weight markers. FIG. 7: Western Blot control of ACN53 derived from column chromatography and CsCl-ultracentrifugation. Samples identical to those previously described were electrophoresed on an 8-16% gradient gel and then transferred to a PVDF membrane. The blot was first incubated with 5 μg / ml Cytimmune rabbit 1 gG anti-adenovirus type 5 antibody, then incubated with Amersham's horseradish peroxidase conjugated with anti-rabbit 1 g and electrochemical Deployed using automatic detection. FIG. 8: Expression of p53 gene product in Saos-2 cells. Two different lots of chromatographically produced ACN53 were analyzed by Western blot for the ability to undergo gene transfer to p53-nul1 Saos-2 cells. The semi-pure DEAE fraction is shown in lanes 7 and 8, and the final product is shown in lanes 5 and 6. p53-expressing SW480 cells were used as positive controls; uninfected Saos-2 cells were used as negative controls.

Claims (2)

A method for determining the number of complete virus particles in an eluent sample from a chromatographic operation comprising:
a) create a standard curve of the number of virus particles at the selected absorbance;
b) Chromatography on samples containing virus particles with anion exchange resin; c) monitoring the chromatography of step (b) at the selected absorbance above;
d) A method comprising measuring the total number of virus particles in the eluent by comparing the absorbance value obtained in step (c) with the standard curve of step (a). The process according to claim 1, wherein the chromatographic operation is carried out on an anion exchange resin having QAE groups covalently bonded to a polystyrene / divinylbenzene copolymer support.

Images